Spontaneous combustion of organic material is a complicated process and a number of conditions must be fulfilled in order for it to take place. Although many of the conditions under which spontaneous combustion takes place are not as yet completely understood, it is known that all spontaneous combustion processes require an accurately defined environment.
The features defining such an environment include suitable heat insulation and a sufficient air supply, although the amount of air required is normally very small. It is also known that the heating process preceding the stage at which the product bursts into flame (e.g., the uncontrolled propagation of an oxidation process) is caused either by thermophilic bacteria or by some form of auto-oxidation process as a result of production processes. The former is true in respect to a number of organic substances, such as sawdust, wood waste, hay, peat, wheat, corn, flour, bark, woodchips, pine needles, green wood, and other organic materials, while the latter case is true with respect to a number of other self-combustible materials, such as oil, gas, coal, fiberboard, sulfur, powder iron, and iron chips. Also, the presence of moisture and impurities having a catalytic effect are often conditions under which spontaneous combustion is likely to occur.
Accordingly, the use of bins, bunkers, and silos to store the above products has been problematic, because the products inside can begin to spontaneously combust. The generated fire, however, cannot be seen from outside of the bins, bunkers, or silos. Only a significant rise in heat can be detected. When a fire bums deep inside a silo, it makes a pocket that will fill with combustion gasses and air.
To address such problems, piercing type nozzles for use with fire extinguishing equipment have been utilized in the past and in one particular device the nozzle has a pointed head, which is manually forced through the shell or barrier of the silo or bin that is to be penetrated. Oftentimes the strength of the barrier is sufficient to prevent the manually forcing of the penetrating nozzle into the silo or bin. In one attempt to overcome this problem, explosively operated piercing applicators have been utilized. This type of applicator is not practical for use in a possibly explosive atmosphere such as would often be encountered in a fire within a silo, bin, or bunker. Sledgehammer operated penetrating fire extinguishing nozzles have also been proposed.
One such piercing type nozzle is disclosed in U.S. Pat. No. 2,548,621 to Rutledge. The penetrating nozzle includes a single section, which can be driven into a bulk powder material or hay bale, for example. Once the piercing nozzle has been driven into the material, the piercing nozzle can inject a substance, such as a fire-fighting substance, into the material to extinguish a fire. Accordingly, the penetrating nozzle can be connected to a portable extinguisher to assist in extinguishing a fire.
As disclosed, the penetrating nozzle, however, can only inject one fire-fighting agent and cannot detect the precise location of the fire within the material in which the piercing nozzle has been injected into. Further, the disclosed penetrating nozzle cannot draw a sample of the combustion gas from the material to assist in determining the location of the fire within the material. The piercing nozzle disclosed is of a predetermined size and, therefore, can only be used in a limited area within the combustible material. Accordingly, the piercing nozzle may not be effective in larger silos, bins, or bunkers.
Another piercing nozzle is disclosed in U.S. Pat. No. 4,219,084 to Gray et al. The piercing nozzle includes a built-in hammer (a slide hammer), so that the piercing nozzle can be carried to a location where the slide hammer is used to push the piercing nozzle into a device, such as a bin, or material. More particularly, the disclosed piercing nozzle is used to push through the exterior of on aircraft, to extinguish fires that occur inside of the airplane.
As disclosed, the piercing nozzle, however, can only inject one type of fire-fighting material. Further, the piercing nozzle cannot take a combustion gas sample and cannot measure the temperature within the aircraft. Like Rutledge, the piercing nozzle disclosed in Gray et al. is not extendable and, therefore, is restricted in size. Such a limitation prevents the piercing nozzle from being used in larger bins, bunkers, or silos. Additionally, the disclosed piercing nozzle is limited in the amount of force that can be applied to the piercing nozzle by the slide hammer. Accordingly, the piercing nozzle must be used for compartments or devices having a thin exterior or skin, such as an airplane fuselage.
Yet another piercing nozzle is disclosed in U.S. Pat. No. 4,270,612 to Larsson. While the piercing nozzle of Larsson has two tubes, the injection source for both tubes is the same. Accordingly, only one type of fire-fighting material can be used. The piercing nozzle disclosed has multiple orifices for dispersing the fire-fighting material. The orifices are arranged over the whole length of the piercing nozzle in order to spray fire-fighting material over a larger area to extinguish the fire.
The disclosed piercing nozzle, however, cannot measure temperature to locate a fire within a bunker, bin, or silo. Additionally, the entire piercing nozzle must be inserted into the source (e.g., storage bin), which may collapse the pocket of combustible gas, thereby causing an explosion. Such an explosion might cause damage to property or equipment or even death to a firefighter.
The nozzle disclosed in Larsson includes a piercing tip having an angle of approximately 45 degrees. Such an angle makes it more difficult to push the piercing nozzle into the device, because of friction. Finally, the piercing nozzle, as disclosed, does not have an end conducive for driving the piercing nozzle into the device (such as a bin, bunker, or silo). More specifically, the disclosed nozzle is intended for insertion into a tank or device before the potentially combustible materials are stored therein. The main purpose of the piercing nozzle is to push air or seawater into the device as a fluffing agent to drive off combustible gas build-up. Accordingly, the piercing nozzle disclosed is used mainly to prevent fires, not to extinguish them.
Still another piercing nozzle is disclosed in U.S. Pat. No. 4,466,201 to Larsson. The disclosed piercing nozzle is mainly used to provide a drying agent to the material within a device and, therefore, is not intended for temporarily insertion using a hammer or similar device. Rather, the nozzle is intended for permanent installation into the device and is not a fire-fighting apparatus.
The nozzle also comprises a plurality of orifices in order to aerate the materials, such as bulk powder. Although the nozzle is adequate for drying the materials within a tank, the nozzle is not equipped for extinguishing fires that occur within the tank. Further, the nozzle cannot read temperature to determine the precise location of a fire within a bin, bunker, or silo.
Another piercing nozzle is disclosed in U.S. Pat. No. 4,676,319 to Cuthbertson. The piercing nozzle is portable and can bore into a tank or bin, but is mainly intended for gas fires that may occur within the fuselage of an airplane. The piercing nozzle is specifically designed for boring into the device and injecting a fire-fighting agent, such as foam. The disclosed nozzle, however, can only inject one type of fire-fighting agent at a time and cannot measure the temperature within the device to determine the precise location of the fire.
More specifically, the disclosed piercing nozzle is designed to drill a hole where one did not exist previously. Instead of relying on a hammer or similar device to pound the piercing nozzle into the source, the disclosed piercing nozzle relies on mechanical energy (not human energy) to push the piercing nozzle. Such an ability is not generally necessary in bins, silos or other types of storage tanks, because such devices generally have openings or portholes for inserting a piercing nozzle. The disclosed piercing nozzle, therefore, would generally be used for fuselage fires in aircraft and vehicles. Further, the piercing nozzle is not capable of extracting a sample of combustion gas in order to determine the location of the fire and whether the fire has been properly extinguished.
Other devices, such as those disclosed in U.S. Pat. Nos. 5,167,285, 5,275,243, and 5,312,041 to Williams et al., have been designed for fighting fires using a dry powder. The disclosed dry powder guns, however, are not designed for fighting internal fires within a bin, bunker, or silo. Instead, these devices are used to fight surface fires. The disclosed dry powder guns spray the fire-fighting agent on the surface of a fire and, therefore, are not extendable, do not read temperatures, and do not pierce sources, such as storage bins. Although one of the dry powder guns can adjust the stream of fire-fighting agent, while another can produce two types of fire-fighting agents to apply to a fire, none of the devices disclosed could effectively be used to fight fires that occur internally within a device.
What is needed is a piercing nozzle for penetrating a storage tank (such as a bin, bunker, or silo) that can be extended to a desirable length, dispense at least two fire-fighting agents, read the temperature within the storage tank, extract combustion gas from within the storage tank, and which can be inserted into the storage tank with the use of a sledgehammer or similar device. It is to such a device that the present invention is primarily directed.